Source code

001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2020, by Object Refinery Limited and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 */
028
029package org.jfree.chart.text;
030
031import java.awt.Color;
032import java.awt.Font;
033import java.awt.FontMetrics;
034import java.awt.Graphics2D;
035import java.awt.Paint;
036import java.awt.font.LineMetrics;
037import java.awt.geom.Rectangle2D;
038import java.io.IOException;
039import java.io.ObjectInputStream;
040import java.io.ObjectOutputStream;
041import java.io.Serializable;
042import org.jfree.chart.ui.Size2D;
043import org.jfree.chart.ui.TextAnchor;
044import org.jfree.chart.util.SerialUtils;
045
046/**
047 * A text item, with an associated font, that fits on a single line (see 
048 * {@link TextLine}).  Instances of the class are immutable.
049 */
050public class TextFragment implements Serializable {
051
052    /** For serialization. */
053    private static final long serialVersionUID = 4465945952903143262L;
054    
055    /** The default font. */
056    public static final Font DEFAULT_FONT = new Font("Serif", Font.PLAIN, 12);
057    
058    /** The default text color. */
059    public static final Paint DEFAULT_PAINT = Color.BLACK;
060    
061    /** The text. */
062    private String text;
063    
064    /** The font. */
065    private Font font;
066    
067    /** The text color. */
068    private transient Paint paint;
069    
070    /** 
071     * The baseline offset (can be used to simulate subscripts and 
072     * superscripts). 
073     */
074    private float baselineOffset;
075    
076    /**
077     * Creates a new text fragment.
078     * 
079     * @param text  the text ({@code null} not permitted).
080     */
081    public TextFragment(String text) {
082        this(text, DEFAULT_FONT, DEFAULT_PAINT);
083    }
084    
085    /**
086     * Creates a new text fragment.
087     * 
088     * @param text  the text ({@code null} not permitted).
089     * @param font  the font ({@code null} not permitted).
090     */
091    public TextFragment(String text, Font font) {
092        this(text, font, DEFAULT_PAINT);
093    }
094
095    /**
096     * Creates a new text fragment.
097     * 
098     * @param text  the text ({@code null} not permitted).
099     * @param font  the font ({@code null} not permitted).
100     * @param paint  the text color ({@code null} not permitted).
101     */
102    public TextFragment(String text, Font font, Paint paint) {
103        this(text, font, paint, 0.0f);
104    }
105
106    /**
107     * Creates a new text fragment.
108     * 
109     * @param text  the text ({@code null} not permitted).
110     * @param font  the font ({@code null} not permitted).
111     * @param paint  the text color ({@code null} not permitted).
112     * @param baselineOffset  the baseline offset.
113     */
114    public TextFragment(String text, Font font, Paint paint,
115            float baselineOffset) {
116        if (text == null) {
117            throw new IllegalArgumentException("Null 'text' argument.");  
118        }
119        if (font == null) {
120            throw new IllegalArgumentException("Null 'font' argument.");
121        }
122        if (paint == null) {
123            throw new IllegalArgumentException("Null 'paint' argument.");
124        }
125        this.text = text;
126        this.font = font;
127        this.paint = paint;
128        this.baselineOffset = baselineOffset;
129    }
130
131    /**
132     * Returns the text.
133     * 
134     * @return The text (possibly {@code null}).
135     */
136    public String getText() {
137        return this.text;
138    }
139    
140    /**
141     * Returns the font.
142     * 
143     * @return The font (never {@code null}).
144     */
145    public Font getFont() {
146        return this.font;
147    }
148    
149    /**
150     * Returns the text paint.
151     * 
152     * @return The text paint (never {@code null}).
153     */
154    public Paint getPaint() {
155        return this.paint;
156    }
157    
158    /**
159     * Returns the baseline offset.
160     * 
161     * @return The baseline offset.
162     */
163    public float getBaselineOffset() {
164        return this.baselineOffset;   
165    }
166    
167    /**
168     * Draws the text fragment.
169     * 
170     * @param g2  the graphics device.
171     * @param anchorX  the x-coordinate of the anchor point.
172     * @param anchorY  the y-coordinate of the anchor point.
173     * @param anchor  the location of the text that is aligned to the anchor 
174     *                point.
175     * @param rotateX  the x-coordinate of the rotation point.
176     * @param rotateY  the y-coordinate of the rotation point.
177     * @param angle  the angle.
178     */
179    public void draw(Graphics2D g2, float anchorX, float anchorY, 
180            TextAnchor anchor, float rotateX, float rotateY, double angle) {
181        g2.setFont(this.font);
182        g2.setPaint(this.paint);
183        TextUtils.drawRotatedString(this.text, g2, anchorX, anchorY 
184                + this.baselineOffset, anchor, angle, rotateX, rotateY);
185    }
186    
187    /**
188     * Calculates the dimensions of the text fragment.
189     * 
190     * @param g2  the graphics device.
191     * 
192     * @return The width and height of the text.
193     */
194    public Size2D calculateDimensions(Graphics2D g2) {
195        FontMetrics fm = g2.getFontMetrics(this.font);
196        Rectangle2D bounds = TextUtils.getTextBounds(this.text, g2, fm);
197        Size2D result = new Size2D(bounds.getWidth(), bounds.getHeight());
198        return result;
199    }
200    
201    /**
202     * Calculates the vertical offset between the baseline and the specified 
203     * text anchor.
204     * 
205     * @param g2  the graphics device.
206     * @param anchor  the anchor.
207     * 
208     * @return the offset.
209     */
210    public float calculateBaselineOffset(Graphics2D g2, TextAnchor anchor) {
211        float result = 0.0f;
212        FontMetrics fm = g2.getFontMetrics(this.font);
213        LineMetrics lm = fm.getLineMetrics("ABCxyz", g2);
214        if (anchor.isTop()) {
215            result = lm.getAscent();
216        }
217        else if (anchor.isHalfAscent()) {
218            result = lm.getAscent() / 2.0f;
219        }
220        else if (anchor.isVerticalCenter()) {
221            result = lm.getAscent() / 2.0f - lm.getDescent() / 2.0f;
222        }
223        else if (anchor.isBottom()) {
224            result = -lm.getDescent() - lm.getLeading();
225        }
226        return result;                                             
227    }
228    
229    /**
230     * Tests this instance for equality with an arbitrary object.
231     * 
232     * @param obj  the object to test against ({@code null} permitted).
233     * 
234     * @return A boolean.
235     */
236    @Override
237    public boolean equals(Object obj) {
238        if (obj == null) {
239            return false;   
240        }
241        if (obj == this) {
242            return true;   
243        }
244        if (obj instanceof TextFragment) {
245            TextFragment tf = (TextFragment) obj;
246            if (!this.text.equals(tf.text)) {
247                return false;   
248            }
249            if (!this.font.equals(tf.font)) {
250                return false;   
251            }
252            if (!this.paint.equals(tf.paint)) {
253                return false;   
254            }
255            return true;
256        }
257        return false;
258    }
259
260    /**
261     * Returns a hash code for this object.
262     * 
263     * @return A hash code.
264     */
265    @Override
266    public int hashCode() {
267        int result;
268        result = (this.text != null ? this.text.hashCode() : 0);
269        result = 29 * result + (this.font != null ? this.font.hashCode() : 0);
270        result = 29 * result + (this.paint != null ? this.paint.hashCode() : 0);
271        return result;
272    }
273
274    /**
275     * Provides serialization support.
276     *
277     * @param stream  the output stream.
278     *
279     * @throws IOException  if there is an I/O error.
280     */
281    private void writeObject(ObjectOutputStream stream) throws IOException {
282        stream.defaultWriteObject();
283        SerialUtils.writePaint(this.paint, stream);
284    }
285
286    /**
287     * Provides serialization support.
288     *
289     * @param stream  the input stream.
290     *
291     * @throws IOException  if there is an I/O error.
292     * @throws ClassNotFoundException  if there is a classpath problem.
293     */
294    private void readObject(ObjectInputStream stream) throws IOException, 
295            ClassNotFoundException {
296        stream.defaultReadObject();
297        this.paint = SerialUtils.readPaint(stream);
298    }
299   
300}
301